Field of the Invention
The present invention relates to a variable intake valve with a spring, and more particularly, to a variable intake valve with a spring to solve a problem in that a spring valve is applied to adjust the opening point in time (i. e., a timely opening) of the variable intake valve according to taste of a driver and according to an exemplary embodiment of the present invention, the intake valve is open or blocked according to a driving mode selected by the driver even when negative pressure with small amount of air is loaded, thereby the intake valve is opened only at one point in time, not at a lot of points in time as in a conventional art which does not reflect taste of a driver.
Description of Related Art
Generally, an intake system of a vehicle engine is designed such that air that has passed through an air cleaner pushes a flap of an air flow meter and appropriate amount of air can be inhaled to a combustion chamber according to the opening degree of a throttle valve.
At this time, the inflowing air has an influence on output and fuel efficiency of an engine, therefore it is evaluated to be preferable that oversupply of fuel is retrained by minimizing inhalation resistance and allowing a mixture of fuel and air to be an ideal air/fuel ratio.
Accordingly, a throttle body, a substantial passage through which air is inflow is better to have a structure capable of reducing the resistance of pipelines, and also needs to be designed such that air flow resistance to a valve is to be small when the throttle valve is opened and closed.
The air volume required for combustion is varied when a vehicle drives or idly rotates, and especially is relevant to output when driving, therefore there is a limit in improving an output with only the degree of opening and closing of a throttle valve.
Accordingly, an intake port is divided into two passages, one passage of which forms a spiral to achieve a swirl operation, and also a swirl control valve is installed in the other passage and thereby is given a function of a variable intake valve that blocks the passage during low-speed driving and allows the passage to open during high-speed driving.
Meanwhile, since a device for opening and closing of a conventional variable intake valve is designed to control an actuator with ECU, a solenoid that is electronically controlled becomes a requisite component and also a control portion of ECU needs to be additionally mounted, and thus structural complexity thereof is inevitable.
As a result, even though there is an opening and closing device of a variable intake valve through DC motor system, since this is controlled with ECU in addition to separate DC motor, a solenoid that is electronically controlled becomes a requisite component and thus manufacturing costs are increased and its structure becomes complicated.
Meanwhile, fresh air (external air) is supplied to a combustion chamber of an engine through an intake duct 20→an air cleaner 40→an intake hose 30 during an intake stroke of an engine piston, and FIG. 1 is a view illustrating a variable intake valve using a conventional spring. The operation principle is as follows
New air enters into an engine through two intake ports such that a spring valve 10 is closed at a low output and the spring valve 10 is open at a high output to supply much more external air to the engine than at the low output.
Meanwhile, reviewing an operating principle of a spring valve with reference to FIGS. 2A to 2C, FIG. 2A is a view showing a closed state of the spring valve, FIG. 2B is a view showing an open state of the spring valve, and FIG. 2C is a view showing a state that a spring 100 is coupled to a fixing pin 200.
Since much external air supplies to an engine are necessary at a high output than at a low output, when a negative pressure of the inhaled external air (forces for pulling a valve backward) is greater than elastic force (forces for closing a valve) of a spring 100 coupled to an outer circumferential surface of a fixing pin 200, a spring valve 10 is open.
However, this spring valve 10 that is currently used has an advantage that cost is greatly cheap, but the spring valve 10 is open only at one point in time where a negative pressure of the inhaled external air is greater than elastic force of a spring 100 coupled to an outer circumferential surface, and thus has a problem that it is hard to change an opening point in time of the spring valve 10 according to taste of a driver.
That is, in accordance with a selection of a driver it wishes to implement a sporty sound color with intake air discharging noise throughout the whole range from low output to high output on “sports mode”, and implement a function of reducing the intake air discharging noise on “comport mode.” However, a spring valve 10 according to a related art is opened only at one point in time, and thus has a problem that a driver does not determine the opening point in time of the spring valve 10.
As the invention related to the spring valve, various prior documents are disclosed, including a conventional art entitled “variable intake mechanical device”, however, inexpensive spring valve is used wherein a technology of tuning the opening point in time of a spring valve at three points in accordance with a selection of a driver, like the present invention, is in a poor state.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.